What Will a 4000 Watt Generator Run? 

So you’re looking to get a generator? 


But will a 4000 watt generator run the basic electronic appliances in your home?


Can it give out enough power to keep food in the refrigerator cold, TV, Lamp lights, and a couple of other small gadgets? 


What will a 4000 watt generator run? and what’s the best 4000 watt generator?


We’ll review these questions in more detail.


But first, you have to understand the starting and running watts of all the electric appliances you are trying to run on the 4000 watt generator. 

Understanding Starting and Running Watts

Starting watt also known as surge watt is the required amount of power to start the motor of an appliance. 


Starting watt is most important on larger appliances, smaller appliances don’t necessarily need it to run. This brings us to Running watt or Continuous watt which is the power needed to run an electronic device over time.  


A typical 4000-watt Generator (Running watt) provides about 33 amps from 120 Volts and about 16.6 amps in 240 volts. 


Surge watts are higher than the continuous watt which why it is important that the power rating of your generator is 4000 watts. Per experience, the starting watt is about 4200 to 4500 watt depending on the model. 

See also: What will a 400 Watt Power Inverter run


Best 4000 Watt Generators

Wattage Demands

ApplianceStarting WattsRunning Watts
Furnace (1/4 HP)1000600
Sump Pump (1/3 HP)1300800
Washing Machine22501150
Window AC 13K BTU28001800
Well Pump21001000

Also Read: Best Power Generator [2022]

Frequently Asked Question (FAQs)

What Will a 4000 Watt Generator Run In a Home? 

The table below contains appliances can you can run and the starting and running watt needed to safely run. 


Will a 4000 Watt Generator Run A Space Heater? 

Yes, a 4000 Watt generator will run an average sized space heaters. Typically, these space heaters requires only around 1600 peak Watts. 


Will A 4000 Watt Generator Run A Microwave? 

Yes, a 4000 Watt generator can run a microwave. Microwaves need around 1200-1300 peak Watts to operate so 4,000 is more than sufficient to run a microwave. 



Will A 4000 Watt Generator Run A Sump Pump? 

Sump pumps are categorized under the larger appliances that consume power. If it’s not important I will advise against running the sump pump completely. 


However, there are small sump pumps (1/3 horsepower) that require about 800 running watts and 1300 starting watts. A ½ Horsepower needs 1050 running watts and 2100 starting watts. 


The starting Watts as you can see requires considerable power. You have to ensure the generator starting watts exceed the running watt watts. If you are yet to buy the generator, we have made a list of the best 2000 watt generators on the market. 


For larger appliances like the sump pump, ensure you have a 240 V outlet on the generator. 


Will A 4000 Watt Generator Run A Central Air Conditioning? 

A 4000 watt generator sufficient to run a standard central air conditioning unit. However, it will not have enough output to power a large 3 ton AC/Unit. 


If you still ignore the warning, you risk breaking your generator or burning the AC motor completely. 


There are generators out there that require less than 2000 watts to run central AC but I recommend you contact the manufacturers to be on the safer side. 


Will A 4000 Watt Generator Require A Transfer Switch? 

Make no mistake of directly connecting your generator to the main electrical system of your house. Larger appliances utilize 200 – 240 volts which could damage appliances or fry your electric lines. 


Use a transfer switch to connect your generator for safe use. A transfer switch is of paramount importance, it’s a matter of life and death if you don’t use it. 


Will A 4000 Watt Generator Run A Refrigerator/Freezer? 

Yes, a 4000 Watt generator will run a refrigerator and freezer. A typical refrigerator/freezer requires a minimum of 1200-2200 surge watts to kick start the motor while it steps down to 700 running watts or below. This is on the condition your refrigerator does not fit in 10 sized adults inside.


Still, this is a rough estimate. You can check your refrigerator or freezer’s power rating by reading the manuals or contacting the manufacturers. 


Ensure your fridge is plugged into a stabilizer. 


This will help in mitigating the risk of damaging the high total harmonic distortion. A 4000-watt generator will be able to run two refrigerators easily. 


Will A 4000 Watt Run A TV? 

Absolutely! A 4000-watt generator will run any type of TV. A Television no matter how large would consume no more than 400 running watts and 500 starting watts. So there you have it, you can run more than 3 TVs on the generator with little trouble. 


Will a 4000 Watt Generator Run A Welder? 

Welding can consume ample power. A 4000-watt generator to run a welding setup might be insufficient. In this case, you should contact your brand’s manufacturer. 


There’s an article where we discussed the best generators for welding activities. The products mentioned in the article have been tested first hand by welders, a guarantee that you have the best generator for the job. 


Will A 4000 Watt Generator Run An Air Compressor? 

Well, it depends on the Air compressor’s horsepower. A ¼ would efficiently run on a 2000 running watts generator. But if compressors are different and you must check the manual to know the running and start watt of the appliance. 


But you can expect a rough estimate of wattage from the following horsepower; 

  • ½ horsepower – Requires 980 running watts and 1600 starting watts 
  • 1 horsepower – requires 1600 running watts and 4500 starting watts. 


From the above, you can see that if the Air compressor is less than one horse then it can run the generator. 4500 starting watts is enough but would likely make your generator perform at more than 90% of its capacity.  


Most Quiet 4000 Watt Generators? 

The Champion 4250 Watt Inverter generator is among one of the most quiet in its power class at 64 dB. However, the most quiet generators in general are solar generators.


Will a 4000 Watt generator Run My Rv?

Yes, a 4000 watt generator is a good option and affordable option for your RV. You will want to review the power needs of the appliances you will be running on the RV to make sure it meets your power needs.


However, you have to deal with noise. If you are irked by the noise produced then you will need a quieter option in an Inverter. Check our top inverter generator reviews.


How long does a 4000 Watt Generator Last? 

The life of your generator depends on how you manage it. How well do you service it? Does it have an enclosure to protect it against harsh weather?


These are questions you need to ask yourself. If you can manage your generator well enough, then you can use it for a decade.


How Many Amps Can A 4000 Watt Generator Handle?

A 4000-watt generator provides about 16 amps, in case of 120 volts or 8 amps in case of 240 volts.


How To Determine Your Wattage Requirements 

Determining your wattage requirement is not rocket science. I know most people would love to skip this part but please don’t. It’s simple as adding your fingers together, well it’s not that easy but you get the point. 


I will make this into a step-by-step list to ease you into the whole process of estimating how many watts you will need. 


  1. Make a list of all the appliances you want to run. You can check the list of wattage estimates below or check your manual. 
  2. Write down the starting and running watts into a table 
  3. Add the running watt required to run the electronics on one side and the starting watts on the other. 
  4. The total number of starting watts and running watts from each side will determine the size of the generator you should buy. 


Today we discussed what items a 4000 watt generator can run. Feel free to view our best 4000 watt generator recommendations above.


Because of its long run times, quiet operation, and affordability we believe the is the best overall in its power class.


The is the most affordable option.



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